Present paper reports on the synthesis and emission analysis of Tb3+ and Eu3+ doped Zn2SiO4 sol-gel powder phosphors by a conventional sol-gel method. A prominent green emission has been observed from Tb3+:Zn2SiO4 and a bright red emission from Eu3+:Zn2SiO4 under an UV source. Such an occurrence has been attributed to the existence of sharp and strong intra 4fn transitions from the rare earth ions. With an excitation at 376 nm, both blue (5D4→7F6) and green (5D4 → 7F5) emissions from Tb3+: Zn2SiO4 have been measured. A red emission (5D0→7F2) from Eu3+: Zn2SiO4 has been measured with an excitation at 394 nm. Observance of both blue (490 nm) and green (546 nm) emissions from Tb3+: Zn2SiO4 could be due to the cross-relaxation processes between 5D3 and 5D4 levels of Tb3+ ions. The color emission mechanisms involved from these sol-gel powder phosphors, have been explained in terms of energy level diagrams. For the, prominent emissions (green and red) the decay curves have been plotted to evaluate emission lifetimes. The structural details of Zn2SiO4 powder phosphors have been investigated based on the measurement of XRD, FTIR, Raman profiles and SEM image. The results reveal that these luminescent powders are in all nanometer sized-grains in spherical form with willemite structures.